Is this the last word in linguistics?

For 40 years Noam Chomsky's ideas on language have held. Now, says Steve Connor, there's a new theory to get our tongues round

Every healthy child is born with the vocal and mental equipment necessary to learn a language. Indeed, language - as opposed to simple sound communication - is one attribute that distinguishes humans from all other animals. And yet scientists find it difficult to understand why we speak so many different languages, with such a panoply of sounds and grammatical constructions.

Every healthy child is born with the vocal and mental equipment necessary to learn a language. Indeed, language - as opposed to simple sound communication - is one attribute that distinguishes humans from all other animals. And yet scientists find it difficult to understand why we speak so many different languages, with such a panoply of sounds and grammatical constructions.

For 40 years, the study of languages has been dominated by Noam Chomsky's idea of "universal grammar", a basic set of linguistic rules that are determined ultimately by our genes. Steven Pinker developed the idea further in his 1995 book The Language Instinct, in which he argued that language is not simply a cultural invention but a biological system, partly learned and partly innate. According to this idea, we are each born with a template for grammatical construction and it is our upbringing that determines which language we end up speaking as a mother tongue.

Not all linguistics scholars, however, are entirely happy with this idea. At the recent meeting of the American Association for the Advancement of Science in Washington DC, the linguist Professor Andrew Wedel of Arizona University challenged the Chomsky model of universal grammar with his own view that language has an innate property of self-organisation.

In a nutshell, says Wedel, self-organisation is when a system evolves a large structure from repeated small-scale interactions between its smaller elements. "Sand dunes in the desert or ripples at the bottom of a streambed come about from the air or water flowing over them and the way individual grains of sand happen to bounce against one another," he says. "No individual sand grain knows that it is part of a sand dune or streambed. It is these repeated, small-scale interactions that, over time, result in this big structure that has a lot of order."

Language has an in-built capacity for self-organisation and it is this trait, rather than the universal grammar of Chomsky, that creates the wealth of mother tongues (some 6,000 or so) in the world. "Languages are the ripples in the dunes and the grains of sand are our conversations, generations talking to each other and learning things and slowly creating these larger ripples in time," Wedel says.

He has tested the idea by getting computers to talk to one another using a simple proto-language based on a continuum of vowel sounds ranging from the "eee" made when the jaw is closed to the "aaah" when the jaw is open. After running thousands of simulated "conversations" he found that the computers began to simplify the range of sounds they used and even worked out simple rules in an attempt to eliminate the possibility of misunderstandings resulting from two "words" sounding similar.

"The basic universal grammar model says that the lexicon and grammar algorithm are entirely separate from one another. They don't feed back to one another, they don't communicate much," says Wedel. "This particular model, on the other hand, suggests that the particular features of a lexicon may influence how grammar evolves, and vice versa."

The problem with the Chomsky model of language is that it has to accept many exceptions to the basic rules. "If you look very hard, you can find some group of people somewhere speaking a language that does it differently," Wedel says. "I think there is a big shift from the explanation from a single level, advocated by Chomsky, that one grammar algorithm is coded in our genes, to a more layered set of explanations where structure gradually emerges, over time, through many cycles of talking and learning."